Acoustic waveform processing is frequently used to estimate properties of a geological formation. Acoustic waveform data may be collected using an acoustic logging tool. The acoustic logging tool typically includes an acoustic source (transmitter), and a set of receivers that are spaced several inches or feet apart. An acoustic signal is transmitted by the acoustic source, and received at the receivers of the tool, which are spaced apart from the acoustic source. Measurements are repeated every few inches as the tool is drawn up (or down) the borehole. The acoustic signal from the acoustic source travels through the formation adjacent to the borehole to the receiver array. The arrival times and perhaps other characteristics of the received signals are recorded. Typically, compressional wave (P-wave), shear wave (S-wave), and Stoneley wave arrivals are observed by the receivers and are processed into an acoustic waveform data format. The acoustic waveform data can be processed to determine other formation characteristics such as formation slowness (which is the inverse of acoustic speed), from which pore pressure, porosity, and other formation properties can be determined.
Many different techniques are known in the art for processing the acoustic waveform data in order to obtain information regarding the borehole, the formation, or both. Typically, the processing involves digitizing the received signal at a desired sampling rate and then processing the digitized samples according to desired techniques.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.